Sense-improving agent

ABSTRACT

A purpose of the present invention is to provide a sense-improving agent which is safe and, when routinely taken or applied to the skin, exerts an effect of improving deterioration in peripheral sensation. Another purpose of the present invention is to provide a food, a drink, a feed or a cosmetic for improving sensation which exerts an effect of improving deterioration in peripheral sensation when orally taken or applied to the skin. The sense-improving agent comprises, as the active ingredient, a basic protein fraction derived from milk or a degraded basic protein fraction derived from milk. By orally taking the basic protein fraction derived from milk or the degraded basic protein fraction derived from milk or applying the same directly to the skin, deterioration in sensation, in particular, peripheral sensation can be improved. Thus, a food, a drink, a feed or a cosmetic for improving sensation can be obtained.

TECHNICAL FIELD

The invention relates to a skin sensitivity improving agent thatincludes a basic protein fraction or a degraded basic protein fractionas an active ingredient and improves deterioration in peripheralsensation, and a skin sensitivity improving food, drink, feed, orcosmetic that includes the skin sensitivity improving agent.

BACKGROUND ART

In recent years, an increase in age-related diseases such asosteoporosis, dementia and the like has become a serious social issuealong with aging of population. Various drugs have been developed toprevent or improve such age-related diseases. However, since drugsalways need to take side effects into consideration, in recent years,attempts have been made to prevent or improve age-related diseasesthrough a change in eating habits or intake of a specific foodingredient. For example, it is known that osteoporosis is prevented orimproved by intake of a basic protein contained in cow milk (see PatentDocument 1). A dementia therapeutic agent that prevents or improvesAlzheimer-type dementia and contains sphingomyelin which is one of thephospholipids containing relatively abundantly in cow milk as an activeingredient has also been known (see Patent Document 2).

Deterioration in peripheral sensation can be known as one of theage-related symptoms. The deterioration in peripheral sensation alsooccurs due to not only aging, but also diseases such as diabetes and thelike. Deterioration in peripheral sensation may occur followingtroubles; for example, as it can't feel hot immediately when touching ahot object, a risk of burns or the like increases or the discovery of aninjury becomes delay due to deterioration in pain sensation. In recentyear, in order to decrease such a risk, studies that improvedeterioration in peripheral sensation due to ageing or diseases havebeen conducted. For example, it has been reported that sphingomyelinaseor phosphatidylcholine-specific phospholipase C, which are enzymes thatincrease biosynthesis of endogenous ceramides promote differentiation ofPC-12 cells which is one of the neural cell lines through the secretionof neurotrophic factors from Swiss 3T3 fibroblast cells (see Non-patentDocument 1). However, since ceramides and the above enzymes are not foodingredients, it is necessary to take account of safety. Therefore, asafe agent that is effective to improve deterioration in peripheralsensation through daily intake or skin application has been desired.

PRIOR ART DOCUMENT Patent Document

Patent Document 1: JP-A-H08-151331

Patent Document 2: JP-A-2003-146883

Non-Patent Document

Non-patent Document 1: Norimichi Nakahata and Satoko Okubo, Studies onExpression Mechanism of Physiological Functions of Ceramides Having SkinProtection Function, Annual Report of Cosmetology, Vol. 10, 2002

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

An object of the present invention is to provide a safe and skinsensitivity improving agent that is effective to improve deteriorationin peripheral sensation through daily intake or skin application.Another object of the present invention is to provide asensation-improving food, drink, feed, or cosmetic that is effective toimprove deterioration in peripheral sensation through oral intake orskin application.

Means for Solving the Problems

The inventors of the invention, in consideration of those problems,searched for a safe component that exhibits an excellent improvementeffect to the deterioration in sensation. As a result, the inventorsfound that deterioration in sensation, particularly peripheralsensation, can be improved by oral intake or skin application of a basicprotein fraction derived from milk (hereinafter referred to as“milk-derived basic protein fraction”) or a degraded basic proteinfraction obtained by degrading the milk-derived basic protein fractionusing a protease (hereinafter referred to as “degraded milk-derivedbasic protein fraction”). The inventors thus completed a skinsensitivity improving agent by utilizing the milk-derived basic proteinfraction and/or the degraded milk-derived basic protein fraction as anactive ingredient. The inventors also found that a skin sensitivityimproving food, drink, feed, or cosmetic can be obtained by adding theskin sensitivity improving agent to a food, drink, feed, or the like,respectively. These findings have led to completion of the invention.

Specifically, the invention provides the following.

(1) A skin sensitivity improving agent including a milk-derived basicprotein fraction as an active ingredient.

(2) The skin sensitivity improving agent according to (1), wherein themilk-derived basic protein fraction contains basic amino acids in anamount of 15 wt % or more based on total amino acids.

(3) The skin sensitivity improving agent according to (1) or (2),wherein the milk-derived basic protein fraction is obtained by bringingmilk or a milk-derived raw material into contact with a cation-exchangeresin to allow basic proteins to be adhered on the cation-exchangeresin, and eluting the fraction adhered on the cation-exchange resinusing an eluant having a sodium chloride concentration of 0.1 to 1.0 M.

(4) A skin sensitivity improving agent including a degraded milk-derivedbasic protein fraction as an active ingredient, the degradedmilk-derived basic protein fraction being obtained by treating themilk-derived basic protein fraction according to any one of (1) to (3)with a protease.

(5) The skin sensitivity improving agent according to (4), wherein theprotease is at least one protease selected from the group consisting ofpepsin, trypsin, chymotrypsin, and pancreatin.

(6) A skin sensitivity improving food, drink, feed, or cosmeticincluding the milk-derived basic protein fraction or the degradedmilk-derived basic protein fraction according to any one of (1) to (5).

(7) A method for improving sensation of a mammal including administeringa composition that includes a milk-derived basic protein fraction to themammal via oral administration or application on skin.

(8) The method according to (7), wherein the milk-derived basic proteinfraction contains basic amino acids in an amount of 15 wt % or morebased on total amino acids.

(9) The method according to (7) or (8), wherein the milk-derived basicprotein fraction is obtained by bringing milk or a milk-derived rawmaterial into contact with a cation-exchange resin to allow basicproteins to be adhered on the cation-exchange resin, and eluting thefraction adhered on the cation-exchange resin using an eluant having asodium chloride concentration of 0.1 to 1.0 M.

(10) A method for improving sensation of a mammal includingadministering a composition that includes a degraded milk-derived basicprotein fraction to the mammal via oral administration or application onskin, the degraded milk-derived basic protein fraction being obtained bytreating the milk-derived basic protein fraction according to any one of(7) to (9) with a protease.

(11) The method according to (10), wherein the protease is at least oneprotease selected from the group consisting of pepsin, trypsin,chymotrypsin, and pancreatin.

Effects of the Invention

The invention can thus provide a skin sensitivity improving agent thatincludes a milk-derived basic protein fraction or a degradedmilk-derived basic protein fraction as an active ingredient, and a skinsensitivity improving food, drink, feed, or cosmetic that includes amilk-derived basic protein fraction or a degraded milk-derived basicprotein fraction. The skin sensitivity improving agent according to theinvention exhibits an effect that improves deterioration in peripheralsensation.

EMBODIMENTS FOR CARRYING OUT THE INVENTION

The invention is characterized in that a milk-derived basic proteinfraction or a degraded milk-derived basic protein fraction are used asactive ingredients. The milk-derived basic protein fraction is obtainedfrom mammalian milk such as cow milk, human milk, goat milk, or ewemilk, and the degraded milk-derived basic protein fraction is obtainedby treating the milk-derived basic protein fraction with a protease. Themilk-derived basic protein fraction has the following properties.

1) The milk-derived basic protein fraction comprises several types ofproteins having a molecular weight of 3,000 to 80,000 determined bysodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE).

2) The milk-derived basic protein fraction includes proteins in anamount of 95 wt % or more, and includes a small amount of fats and ash.

3) The milk-derived basic protein fraction mainly includes lactoferrinand lactoperoxidase as proteins.

4) The milk-derived basic protein fraction has basic amino acids, suchas lysine, histidine, arginine and the like in an amount of 15 wt % ormore based on the total amino acids.

The basic protein fraction may be obtained by applying a milk-derivedraw material, such as skim milk, whey or the like to a cation-exchangeresin to adhered the basic proteins on the cation-exchange resin,eluting the basic protein fraction adhered on the cation-exchange resinby using an eluant having a sodium chloride concentration of 0.1 to 1 M,collecting the eluted fraction, which is desalted and concentrated byusing a reverse osmosis (RO) membrane, electrodialysis (ED), or thelike, and optionally drying the resulting product, for example.

The following methods have been known as a method of obtaining amilk-derived basic protein fraction; a method of obtaining the fractionby contacting milk or a milk-derived raw material with a cationexchanger to adhere on the cation exchanger, and eluting the basicprotein fraction adhered on the cation exchanger using an eluant havinga pH of more than 5 and an ionic strength of more than 0.5(JP-A-5-202098), a method of obtaining the fraction using an alginicacid gel (JP-A-61-246198), a method of obtaining the fraction from wheyusing porous inorganic particles (JP-A-1-86839), a method of obtainingthe fraction from milk using a sulfated ester compound (JP-A-63-255300),or the like. A basic protein fraction obtained by such a method may beused in the invention. The degraded milk-derived basic protein fractionhas the same amino acid composition as that of the milk-derived basicprotein fraction. For example, the degraded milk-derived basic proteinfraction may be obtained as a peptide composition having an averagemolecular weight of 4,000 or less by treating a milk-derived basicprotein fraction obtained by the above methods with a protease such aspepsin, trypsin, or chymotrypsin, and optionally treating the resultingproduct with a protease such as pancreatin or the like.

The milk-derived basic protein fraction or the degraded milk-derivedbasic protein fraction may be used directly as the skin sensitivityimproving agent according to the invention. Note that the skinsensitivity improving agent may be further mixed a raw material or thelike that is normally used for drugs, food, drink, and feed, such assaccharides, lipids, proteins, vitamins, minerals, or flavors, or thelike, in addition to the milk-derived basic protein fraction or thedegraded milk-derived basic protein fraction, and the skin sensitivityimproving agent may be prepared into a powdered drug, granules, atablet, a capsule, a drinkable preparation, or the like by aconventional method. The skin sensitivity improving agent may also beused in common application form such as emulsion, cream, lotion, massagemask, or the like. The skin sensitivity improving agent in preparationform may be prepared by a conventional method while appropriately addingthe milk-derived basic protein fraction or the degraded milk-derivedbasic protein fraction used as an active ingredient in the invention,and may be used as a cosmetic. Another component, e.g., ceramide,sphingomyelinase, or sphingomyelin or the like that exhibits a skinsensitivity improving effect may be used in combination with themilk-derived basic protein fraction or the degraded milk-derived basicprotein fraction. In the experiments described later using mice, theperipheral sensation was improved by orally administering themilk-derived basic protein fraction or the degraded milk-derived basicprotein fraction in an amount of 10 mg/kg weight or more, and preferably20 mg/kg weight or more per mouse. Therefore, deterioration insensation, particularly peripheral sensation, is expected to be improvedwhen an adult generally takes the milk-derived basic protein fraction orthe degraded milk-derived basic protein fraction in an amount of 10mg/day or more, and preferably 20 mg/day or more, and thus it is desiredto take the above necessary quantity. When applying the milk-derivedbasic protein fraction or the degraded milk-derived basic proteinfraction to skin, the skin liniment may contain the milk-derived basicprotein fraction or the degraded milk-derived basic protein fraction inan amount of 0.001 to 40 wt %, and preferably 0.1 to 10 wt %, based onthe total amount of the skin liniment.

A skin sensitivity improving food or drink according to the inventionmay be produced by mixing the milk-derived basic protein fraction or thedegraded milk-derived basic protein fraction to a normal food or drink,such as yogurt, milk-based drink, wafer, dessert or the like. It ispreferable that the skin sensitivity improving food or drink contain themilk-derived basic protein fraction or the degraded milk-derived basicprotein fraction in an amount of 0.5 to 2000 mg per 100 g of the food ordrink so that an adult can take the milk-derived basic protein fractionor the degraded milk-derived basic protein fraction in an amount of 10mg/day or more, although the content of the milk-derived basic proteinfraction or the degraded milk-derived basic protein fraction isappropriately determined depending on the type of the food or drink. Askin sensitivity improving feed according to the invention may beproduced by adding the milk-derived basic protein fraction or thedegraded milk-derived basic protein fraction to a normal feed, such aslivestock feed, pet food or the like. It is preferable that the skinsensitivity improving feed contain the milk-derived basic proteinfraction or the degraded milk-derived basic protein fraction in anamount of 0.5 to 2000 mg per 100 g of the feed so that the milk-derivedbasic protein fraction or the degraded milk-derived basic proteinfraction is taken in an amount of 10 mg/day or more.

The method of mixing the milk-derived basic protein fraction or thedegraded milk-derived basic protein fraction may not be particularlylimited. For example, the milk-derived basic protein fraction or thedegraded milk-derived basic protein fraction is suspended or dissolvedin deionized water, and the mixture is stirred and prepared in the formof a drug, food, drink, or feed. The stirring/mixing conditions are notparticularly limited as long as the milk-derived basic protein fractionor the degraded milk-derived basic protein fraction is uniformly mixed.The mixture may be stirred/mixed using an ultra-disperser, aTK-homomixer, or the like. The solution containing the composition mayoptionally be concentrated using an RO membrane, or freeze-dried so thatthe solution can be easily used for a drug, food, drink, or feed. Asterilization treatment conventionally used in the production of a drug,food, drink, or feed may be employed in the invention. Dry-heatsterilization may also be employed for a powdery product. Therefore, itis possible to produce drugs, food, drink, and feed in various forms(e.g., liquid, gel, powder, or granules) that contain the milk-derivedbasic protein fraction or the degraded milk-derived basic proteinfraction of the invention.

The invention is further described below by way of examples and testexamples. Note that the following examples are for illustrative purposesonly, and should not be construed as limiting the invention.

EXAMPLE 1

A column (diameter: 5 cm, height: 30 cm) filled with 400 g of sulfonatedChitopearl (cation-exchange resin; manufactured by Fuji Spinning Co.,Ltd.) was sufficiently washed with deionized water. 40 1 (liters) ofunsterilized skim milk (pH 6.7) was passed through the column at a flowrate of 25 ml/min. The column was then sufficiently washed withdeionized water, and a basic protein fraction adhered on the resin waseluted with a 0.02 M carbonate buffer solution (pH 7.0) containing 0.98M sodium chloride. The eluate was desalted and concentrated using areverse osmosis (RO) membrane, and freeze-dried to obtain 21 g ofpowdery milk-derived basic protein fraction (Example product 1). Themolecular weight of the milk-derived basic protein fraction determinedby sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE)was distributed in the range of 3000 to 80,000. The milk-derived basicprotein fraction had the composition shown in Table 1. The milk-derivedbasic protein fraction was hydrolyzed using 6 N hydrochloric acid at110° C. for 24 hours, and the amino acid composition of the milk-derivedbasic protein fraction was analyzed using an amino acid analyzer(“L-8500” manufactured by Hitachi Ltd.). The results are shown in Table2. The protein composition of the milk-derived basic protein fractionwas analyzed by ELI SA. As shown in Table 3, the milk-derived basicprotein fraction had a lactoferrin content and a lactoperoxidase contentof 40% or more. The basic protein fraction may be used directly as theskin sensitivity improving agent according to the invention.

TABLE 1 Water 1.06 (wt %) Protein 96.50 Fat 0.56 Ash 0.27 Others 1.61

TABLE 2 Aspartic acid 10.1 (wt %) Serine 5.3 Glutamic acid 12.3 Proline4.7 Alanine 5.7 Leucine 10.2 Lysine 8.4 Histidine 2.5 Arginine 7.2Others 33.6

TABLE 3 Lactoferrin 42.5 (wt %) Lactoperoxidase 45.6 Insulin-like growthfactor 1 0.005 Others 11.895

EXAMPLE 2

A column (diameter: 100 cm, height: 10 cm) filled with 30 kg ofcation-exchange resin (SP Toyopearl; manufactured by Tosoh Corporation)was sufficiently washed with deionized water. 3 t of cheese whey (pH6.2) that had been heat-sterilized at 121° C. for 30 seconds was passedthrough the column at a flow rate of 101/min. The column was thensufficiently washed with deionized water, and a basic protein fractionadhered on the resin was eluted with a 0.1 M citrate buffer solution (pH5.7) containing 0.9 M sodium chloride. The eluate was desalted andconcentrated by electrodialysis (ED), and freeze-dried to obtain 183 gof a powdery milk-derived basic protein fraction (Example product 2).The milk-derived basic protein fraction thus obtained may be useddirectly as the skin sensitivity improving agent according to theinvention.

EXAMPLE 3

50 g of the milk-derived basic protein fraction obtained in Example 1was dissolved in 10 1 of distilled water. After the addition of 1%pancreatin (manufactured by Sigma), the mixture was reacted at 37° C.for 2 hours. After completion of the reaction, the protease wasinactivated by heating the mixture at 80° C. for 10 minutes to obtain48.3 g of a degraded milk-derived basic protein fraction (Exampleproduct 3). The degraded milk-derived basic protein fraction thusobtained may be used directly as the skin sensitivity improving agentaccording to the invention.

TEST EXAMPLE 1 Study on Cell Differentiation-Promoting Activity

Swiss 3T3 cells, which is one of the fibroblast cell lines known to bepresent in skin, were cultured for 2 days under the condition thatExample product 1 of the milk-derived basic protein fraction or Exampleproduct 3 of the degraded milk-derived basic protein fraction was addedat a concentration of 0.03 to 1%, respectively (Example product 1: groupA, Example product 3: group B). As a control, Swiss 3T3 cells werecultured for 2 days without adding Example product 1 of the milk-derivedbasic protein fraction or Example product 3 of the degraded milk-derivedbasic protein fraction (group C). PC-12 cells, which is one of theneural cell lines, were cultured adding the culture medium of Swiss 3T3cells, and morphological differentiation of the PC-12 cells wasobserved.

As the results, PC-12 cells were highly differentiated when adding theculture mediums of the group A or B. The above experiment was repeatedseveral times, and the differentiation ratio was determined using anoptical microscope. It was confirmed that 95% or more of the cells weredifferentiated in both cases of group A and B. In contrast, PC-12 cellswere not differentiated when adding the culture medium of the group C.No differentiation was observed using an optical microscope when theexperiment was repeated several times. It was thus confirmed that themilk-derived basic protein fraction obtained in Example 1 and thedegraded milk-derived basic protein fraction obtained in Example 3promoted differentiation of PC-12 cells which is one of the neural celllines.

TEST EXAMPLE 2 Study on Skin Sensitivity Improving Effect UsingExperimental Animals

A skin sensitivity improving effect was evaluated by the hot plate testthat is a thermal stimulation behavioristic approach developed by Woolfeand MacDonald. 24-week-old hairless mice (Hos:HR-1) were divided intothree groups (10 mice/group). Example product 2 (milk-derived basicprotein fraction) was orally administered to each mouse using a sonde inan amount of 0, 10, or 20 mg/kg weight once daily for 4 weeks. Eachmouse was placed on a hot plate at 54° C., and the time elapsed untilthe mouse made an escape behavior such as taking off the foot from thehot plate, standing up, or jumping was measured. The maximum time ofescape behavior positive reaction time that is time until the mouse madean escape behavior after applying thermal stimulation was set to 30seconds. When the escape behavior positive reaction time was 30 secondsor more, the escape behavior positive reaction time was determined to be30 seconds. The results are shown in Table 4.

TABLE 4 Escape behavior Example product 2 positive reaction time  0 mg29.2 ± 0.14 sec 10 mg 22.2 ± 0.17 sec 20 mg 20.1 ± 0.25 sec

As shown in Table 4, the escape behavior positive reaction time tendedto be shortened when administering Example product 2 (milk-derived basicprotein fraction) in an amount of 10 mg, and significantly shortenedwhen administering Example product 2 (milk-derived basic proteinfraction) in an amount of 20 mg. It was thus confirmed thatdeterioration in sensation, particularly peripheral sensation, can beprevented or improved by intake of Example product 2 (milk-derived basicprotein fraction).

TEST EXAMPLE 3 Study on Skin Sensitivity Improving Effect by Oral Intake

Healthy elderly persons (average age: 75±3) who suffered deteriorationin sensation in the hands were divided into following five groups (10subjects/group).

-   -   Group A: the subjects did not take a milk-derived basic protein        fraction or a milk-derived basic protein fraction,    -   Group B: the subjects took the milk-derived basic protein        fraction obtained in Example 1 in an amount of 10 mg for 6        weeks,    -   Group C: the subjects took the milk-derived basic protein        fraction obtained in Example 1 in an amount of 20 mg for 6        weeks,    -   Group D: the subjects took the degraded milk-derived basic        protein fraction obtained in Example 3 in an amount of 10 mg for        6 weeks, and    -   Group E: the subjects took the degraded milk-derived basic        protein fraction obtained in Example 3 in an amount of 20 mg for        6 weeks.        The pain sensation in the palm and the arch of the foot was        measured with 4 criteria (normal, deterioration I, deterioration        II, and deterioration III) before the intake and after the        intake for 6 weeks with reference to the pain sensation in the        medial side of the arm using a pain/touch-pressure sensation        measuring device (Algesiometer; manufactured by Intercross Ltd.)        in accordance with the instruction manual. A questionnaire        survey on an improvement in sensation in the hands was carried        out to each elderly person after the intake for 6 weeks. The        results are shown in Tables 5 to 8.

Measuring Method

The pain sensation was evaluated using five pins having differentthickness at five fulcrum positions. The thinnest pin 1 was rolled alongthe medial side of the arm, and the subject was asked about the degreeof normal pain sensation.

The pin 1 was then rolled along the palm and the bottom of the footwhile sequentially changing the holder fulcrum position to determine thefulcrum position at which the same pain sensation degree as the firstpain sensation occurred. (Evaluation method)

The algesiometer is designed so that the pain sensation occurs to thesame extent between when rolling the pin 1 (fulcrum: 50 g) along themedial side of the arm and when rolling the pin 2 (fulcrum: 50 g) alongthe palm. The pain sensation was evaluated as follows in accordance withthe instruction manual. The pain sensation was evaluated by points, andthe average points were calculated.

-   -   Normal (0 points): The same pain sensation occurred when rolling        the pin 2 (fulcrum: 50 g).    -   Deterioration I (1 point): The same pain sensation occurred when        rolling the pin 1 (fulcrum: 50 g).    -   Deterioration II (2 point): The same pain sensation occurred        when rolling the pin 1 (fulcrum: 60 g).    -   Deterioration III (3 point): The same pain sensation occurred        when rolling the pin 1 (fulcrum: 70 g).

TABLE 5 Deterioration Deterioration Deterioration Average Normal I IIIII value Hand sensation measurement (before intake) Group A 0 2 3 5 2.3Group B 0 1 5 4 2.3 Group C 0 1 5 4 2.3 Group D 0 1 4 5 2.4 Group E 0 15 4 2.3 Hand sensation measurement (after intake for 6 weeks) Group A 02 4 5 2.2 Group B 0 3 5 2 1.9 Group C 2 4 3 1 1.3 Group D 1 2 4 3 1.9Group E 2 2 5 1 1.5

TABLE 6 Deterioration Deterioration Deterioration Average Normal I IIIII value Foot bottom sensation measurement (before intake) Group A 0 23 5 2.3 Group B 0 1 4 5 2.4 Group C 0 1 3 6 2.5 Group D 0 1 6 3 2.2Group E 0 1 4 5 2.4 Foot bottom sensation measurement (after intake for6 weeks) Group A 0 2 3 5 2.3 Group B 1 4 1 4 1.8 Group C 2 3 3 2 1.5Group D 0 3 6 1 1.8 Group E 1 3 5 1 1.6

TABLE 7 Hand sensation Worsened Unaltered Improved Group A 2 7 1 Group B1 5 4 Group C 0 2 8 Group D 0 3 7 Group E 0 2 8

TABLE 8 Foot bottom sensation Worsened Unaltered Improved Group A 2 7 1Group B 0 6 4 Group C 0 2 8 Group D 0 5 5 Group E 0 2 8

As shown in Tables 5 to 8, the sensation in the palm and the bottom ofthe foot tended to be improved by intake of Example product 1(milk-derived basic protein fraction) or Example product 3 (degradedmilk-derived basic protein fraction) in an amount of 10 mg, and wassignificantly improved by intake of Example product 1 (milk-derivedbasic protein fraction) or Example product 3 (degraded milk-derivedbasic protein fraction) in an amount of 20 mg. Deterioration insensation, particularly in peripheral sensation, is expected to beimproved when an adult takes the milk-derived basic protein fraction orthe degraded milk-derived basic protein fraction in an amount of 10mg/day or more generally, and preferably 20 mg/day or more.

EXAMPLE 4 Preparation of Skin Sensitivity Improving Cosmetic (Cream)

A skin sensitivity improving cosmetic (cream) was prepared by mixing thedegraded milk-derived basic protein fraction (Example product 3)obtained in Example 3 with the raw materials in the ratio shown in Table9.

TABLE 9 Glycerol monostearate (self-emulsifiable) 10.0 Purified lanolin6.0 Liquid paraffin 5.0 Jojoba oil 5.0 Parabene 0.3 Degradedmilk-derived basic protein 1.0 fraction (Example production 3) EssenceProper quantity Sterilized ion-exchanged water Balance (total: 100)

TEST EXAMPLE 4 Study on Skin Sensitivity Improving Effect via SkinApplication

Healthy elderly persons (average age: 75±3) who suffered deteriorationin sensation in the hands were divided into groups A and B (15subjects/group). The subjects of the group A were applied the cosmetic(cream) that was prepared in the same manner as Example product 4, butdid not contain a skin sensitivity improving agent, once daily to wholeof the hands and the feet thereof, and the subjects of the group B wereapplied the skin sensitivity improving cosmetic (cream) obtained inExample 4 once daily to whole of the hands and the feet thereof. Theapplication period was 6 weeks. The pain sensation in the palm and thearch of the foot was measured by 4 criteria (normal, deterioration I,deterioration II, or deterioration III) before the application and afterthe application for 6 weeks with respect to the pain sensation in themedial side of the arm using a pain/touch-pressure sensation measuringdevice (Algesiometer; manufactured by Intercross Ltd.) in accordancewith the instruction manual. After the completion of the application for6weeks, a questionnaire survey on an improvement in sensation in thehands was carried out to each subject. The results are shown in Tables10 to 13. The measurement was performed in the same manner as in TestExample 3.

TABLE 10 Deterioration Deterioration Deterioration Average Normal I IIIII value Hand sensation measurement (before application) Group A 0 4 65 2.1 Group B 0 5 4 6 2.1 Hand sensation measurement (after applicationfor 6 weeks) Group A 1 3 7 4 1.9 Group B 3 6 3 3 1.4

TABLE 11 Deterioration Deterioration Deterioration Average Normal I IIIII value Foot bottom sensation measurement (before application) Group A0 5 5 5 2.0 Group B 0 5 6 4 1.9 Foot bottom sensation measurement (afterapplication for 6 weeks) Group A 1 3 5 6 2.1 Group B 2 6 6 1 1.4

TABLE 12 Hand sensation Worsened Unaltered Improved Group A 2 12 1 GroupB 1 6 9

TABLE 13 Foot bottom sensation Worsened Unaltered Improved Group A 3 131 Group B 0 9 5

As shown in Tables 10 to 13, the sensation in the palm and the bottom ofthe foot tended to be improved by applying the skin sensitivityimproving cosmetic (cream) of Example product 4 . It was thus confirmedthat deterioration in sensation, particularly peripheral sensation, isexpected to be improved by applying cream that includes the skinsensitivity improving agent according to the invention.

EXAMPLE 5 Preparation of Skin Sensitivity Improving Liquid NutrientComposition

5 g of Example product 1 (milk-derived basic protein fraction) wasdissolved in 4995 g of deionized water. The solution was stirred by aTK-homomixer (“TK ROBO MICS” manufactured by PRIMIX Corporation) at 6000rpm for 30 minutes to obtain a basic protein fraction solution having abasic protein fraction content of 100 mg/100 g. 4.0 kg of casein, 5.0 kgof a soybean protein, 1.0 kg of fish oil, 3.0 kg of perilla oil, 18.0 kgof dextrin, 6.0 kg of a mineral mixture, 1.95 kg of a vitamin mixture,2.0 kg of an emulsifying agent, 4.0 kg of a stabilizer, and 0.05 kg ofessence were added to 5.0 kg of the milk-derived basic protein fractionsolution. A retort pouch (200 ml) was filled with the mixture. Themixture was then sterilized using a retort sterilizer (class-1 pressurevessel, “RCS-4CRTGN” manufactured by Hisaka Works, Ltd.) at 121° C. for20 minutes to obtain 50 kg of a skin sensitivity improving liquidnutrient composition. The resulting skin sensitivity improving liquidnutrient composition was not observed any precipitation and the like,and did not exhibit abnormal flavor. The skin sensitivity improvingliquid nutrient composition contained the milk-derived basic proteinfraction in an amount of 10 mg/100 g.

EXAMPLE 6 Preparation of Skin Sensitivity Improving Gel-Like Food

2 g of Example product 2 (milk-derived basic protein fraction) wasdissolved in 708 g of deionized water. The solution was stirred using anultra-disperser (“ULTRA-TURRAX T-25” manufactured by IKA Japan) at 9500rpm for 30 minutes. 40 g sorbitol, 2 g of a sour agent, 2 g of essence,5 g of pectin, 5 g of whey protein concentrate, 1 g of calcium lactate,and 235 g of deionized water were added to the solution. After stirringthe mixture, the mixture was filled in a cheer pack (200 ml). Aftersterilizing the mixture at 85° C. for 20 minutes, the pack was tightlysealed, and thus five bags (Net 200 g each) of skin sensitivityimproving gel-like food of the invention were prepared. The resultingskin sensitivity improving gel-like food was not observed anyprecipitation, and did not exhibit abnormal flavor. The skin sensitivityimproving gel-like food contained the milk-derived basic proteinfraction in an amount of 200 mg/100 g.

EXAMPLE 7 Preparation of Skin Sensitivity Improving Drink

2 g of sour agent was dissolved in 706 g of deionized water, and 4 g ofExample product 3 (degraded milk-derived basic protein fraction) wasdissolved in the solution. The solution was stirred using anultra-disperser (“ULTRA-TURRAX T-25” manufactured by IKA Japan) at 9500rpm for 30 minutes. After the addition of 100 g of maltitol, 20 g ofreduced starch syrup, 2 g of essence, and 166 g of deionized water, theresulting mixture was filled into a glass bottle (100 ml). Aftersterilizing the mixture at 95° C. for 15 seconds, the bottle was sealedto obtain ten bottles of skin sensitivity improving drink (100 ml/bottle). The resulting skin sensitivity improving drink was not observedany precipitation, and did not exhibit abnormal flavor. The skinsensitivity improving drink contained the degraded milk-derived basicprotein fraction in an amount of 400 mg/100 g.

EXAMPLE 8 Preparation of Skin Sensitivity Improving Feed

2 kg of Example product 3 (degraded milk-derived basic protein fraction)was dissolved in 98 kg of deionized water. The solution was stirredusing a TK-homomixer (“MARK II 160” manufactured by PRIMIX Corporation)at 3600 rpm for 40 minutes to obtain a degraded milk-derived basicprotein fraction solution containing the degraded milk-derived basicprotein fraction in an amount of 2 g/100 g. 12 kg of soybean cake, 14 kgof skim milk powder, 4 kg of soybean oil, 2 kg of corn oil, 23.2 kg ofpalm oil, 14 kg of corn starch, 9 kg of flour, 2 kg of bran, 5 kg of avitamin mixture, 2.8 kg of cellulose, and 2 kg of a mineral mixture wereadded to 10 kg of the degraded milk-derived basic protein fractionsolution. The mixture was sterilized at 120° C. for 4 minutes to obtain100 kg of skin sensitivity improving dog food. The skin sensitivityimproving dog food contained the degraded milk-derived basic proteinfraction in an amount of 200 mg/100 g.

EXAMPLE 9 Preparation of Skin Sensitivity Improving Agent (Tablet)

The raw materials were mixed in the ratio shown in Table 14. 1 g of theresulting mixture was formed and tableted by a conventional method toobtain a skin sensitivity improving agent of the invention. The skinsensitivity improving agent contained the milk-derived basic proteinfraction in an amount of 100 mg/g.

TABLE 14 Hydrated crystalline glucose 83.5(wt %) Milk-derived basicprotein 10.0 fraction (Example product 1) Mineral mixture 5.0 Sugarester 1.0 Essence 0.5

EXAMPLE 10 Preparation of Skin Sensitivity Improving Cosmetic (Lotion)

A skin sensitivity improving cosmetic (lotion) was prepared by mixingthe raw materials in the ratio shown in Table 15.

TABLE 15 Sorbitol 3.0 Sodium DL-pyrrolidone carboxylate 2.0Carboxymethyl cellulose 0.3 Parabene 0.1 Milk-derived basic protein 1.5fraction (Example product 2) Essence Proper quantity Sterilizedion-exchanged water Balance (total: 100)

1. A skin sensitivity improving agent comprising a milk-derived basicprotein fraction as an active ingredient.
 2. The skin sensitivityimproving agent according to claim 1, wherein the milk-derived basicprotein fraction has basic amino acids in an amount of 15 wt % or morebased on total amino acids.
 3. The skin sensitivity improving agentaccording to claim 1, wherein the milk-derived basic protein fraction isobtained by bringing milk or a milk-derived raw material into contactwith a cation-exchange resin to allow basic proteins to be adhered onthe cation-exchange resin, and eluting a fraction adhered on thecation-exchange resin using an eluant having a sodium chlorideconcentration of 0.1 to 1.0 M.
 4. A skin sensitivity improving agentcomprising a degraded milk-derived basic protein fraction as an activeingredient, the degraded milk-derived basic protein fraction beingobtained by treating the milk-derived basic protein fraction accordingto claim 1 with a protease.
 5. The skin sensitivity improving agentaccording to claim 4, wherein the protease is at least one proteaseselected from a group consisting of pepsin, trypsin, chymotrypsin, andpancreatin.
 6. A skin sensitivity improving food, drink, feed, orcosmetic comprising the milk-derived basic protein fraction or thedegraded milk-derived basic protein fraction according to claim 1.